Abstract: The structure of TritonX 100/ n C 10 H 21 OH/H 2O lamellar liquid crystal system was examined using small angle X ray diffraction (XRD) and electron spin resonance (ESR). The lubrication performance of the lamellar liquid crystal with different compositions was investigated with a high speed ring on block friction and wear tester. The results show that the stability of lamellar liquid crystal decreases with increasing of water content, it increases with the increase of TritonX 100 content. Correspondingly, the lubrication performance of the lamellar liquid crystal worsens with the increase of water content while improves with the increase of TritonX 100 content.